On Tue, 2010-09-07 at 20:03 +0200, Dirk Heinrichs wrote: > Sep 7 19:55:58 oldbox dovecot: master: Error: service(auth): child > 29949 killed with signal 11 (core not dumped) Can you get gdb backtrace? For example one easy way would be to attach gdb into a running auth process: gdb -p `pidof dovecot/auth` cont <make it crash> bt full